Bluetooth: Host: Make function static
Bluetooth: Host: Make function static

`bt_le_create_conn_legacy` is not used outside its file.

Signed-off-by: Aleksander Wasaznik <c0d989573cb73e7c43339e7aaab9bc0cb8ebe8c5@nordicsemi.no>

galak/zephyr,finikorg/zephyr,finikorg/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,galak/zephyr